___

• A. Ben-Israel and T. N. E. Greville , Generalized Inverses: Theory and Applications, CMS Books in Mathematics, 2nd edition, Springer, Heidelberg, 2003.
• E. Boasso and V. Rakocevic, Characterizations of EP and normal Banach algebra elements, Linear Algebra Appl., 435(2) (2011), 342-353.
• W. Chen, On EP elements, normal elements and partial isometries in rings with involution, Electron. J. Linear Algebra, 23 (2012), 553-561.
• A. Dajic, Common solutions of linear equations in a ring, with applications, Electron. J. Linear Algebra, 30 (2015), 66-79.
• A. Dajic and J. J. Koliha, Equations $ax=c$ and $xb=d$ in rings and rings with involution with applications to Hilbert space operators, Linear Algebra Appl., 429(7) (2008), 1779-1809.
• R. E. Hartwig, Block generalized inverses, Arch. Ration. Mech. Anal., 61(3) (1976), 197-251.
• S. Karanasios, EP elements in rings and semigroup with involution and C*-algebras, Serdica Math. J., 41 (2015), 83-116.
• J. J. Koliha and D. Djordjevic, D. Cvetkovic, Moore-Penrose inverse in rings with involution, Linear Algebra Appl., 426(2-3) (2007), 371-381.
• M. Mbekhta, Partial isometries and generalized inverses, Acta Sci. Math. (Szeged), 70 (2004), 767-781.
• D. Mosic and D. S. Djordjevic, Further results on partial isometries and EP elements in rings with involution, Math. and Comput. Modelling, 54(1-2) (2011), 460-465.
• D. Mosic, D. S. Djordjevic and J. J. Koliha, EP elements in rings, Linear Algebra Appl., 431(5-7) (2009), 527-535.
• D. Mosic and D. S. Djordjevic, Partial isometries and EP elements in rings with involution, Electron. J. Linear Algebra, 18 (2009), 761-772.
• R. Penrose, A generalized inverse for matrices, Proc. Cambridge Philos. Soc., 51 (1955), 406-413.
• S. Z. Xu, J. L. Chen and J. Benitez, EP elements in rings with involution, Bull. Malays. Math. Sci. Soc., 42(6) (2019), 3409-3426.
• Z. C. Xu, R. J. Tang and J. C. Wei, Strongly EP elements in a ring with involution, Filomat, 34(6) (2020), 2101-2107. Q. W. Wang and Z. H. He, Solvability conditions and general solution for the fixed Sylvester equations, Automatica, 49 (2013), 2713-2719.
• X. Zhang, A system of generalized sylvester quaternion matrix equations and its applications, Appl. Math. Comput., 273 (2016), 74-81.
• R. J. Zhao, H. Yao and J. C. Wei, Characterizations of partial isometries and two special kinds of EP elements, Czechoslovak Math. J., 70(2) (2020), 539-551.